Modern practice of internal medicine with emergency conditions. Management of patients with heart murmurs

Abstract

Murmurs are defined as sounds heard in addition to the sequence of two to three heart sounds during each heartbeat. The two normal heart sounds–the first heart sound (S1) and the second heart sound (S2)—are produced mainly by the closure of the atrioventricular (tricuspid and mitral) and semilunar (aortic and pulmonary) valves, respectively. Occasionally, an additional heart sound associated with the ventricles filling up with blood may be heard. It is referred to as S3 when it occurs in early diastole and S4 when heard in late diastole after the atrial contraction. Heart murmurs can be systolic, diastolic or continuous and they can be reported with accompanying intensity grades. When clinically insignificant, murmurs are referred to as being "innocent"; they are caused by increased flow or turbulence across anatomically normal valves. Some systolic murmurs may be clinically innocent, while all diastolic and continuous murmurs are abnormal.